On-site treatment of avalanche victims: Scoping review and 2023 recommendations of the international commission for mountain emergency medicine (ICAR MedCom)

INTRODUCTION

The International Commission for Mountain Emergency Medicine (ICAR MedCom) developed updated recommendations for the management of avalanche victims.

METHODS

ICAR MedCom created Population Intervention Comparator Outcome (PICO) questions and conducted a scoping review of the literature. We evaluated and graded the evidence using the American College of Chest Physicians system.

RESULTS

We included 120 studies including original data in the qualitative synthesis. There were 45 retrospective studies (38%), 44 case reports or case series (37%), and 18 prospective studies on volunteers (15%). The main cause of death from avalanche burial was asphyxia (range of all studies 65-100%). Trauma was the second most common cause of death (5-29%). Hypothermia accounted for few deaths (0-4%).

CONCLUSIONS AND RECOMMENDATIONS

For a victim with a burial time ≤ 60 minutes without signs of life, presume asphyxia and provide rescue breaths as soon as possible, regardless of airway patency. For a victim with a burial time > 60 minutes, no signs of life but a patent airway or airway with unknown patency, presume that a primary hypothermic CA has occurred and initiate cardiopulmonary resuscitation (CPR) unless temperature can be measured to rule out hypothermic cardiac arrest. For a victim buried > 60 minutes without signs of life and with an obstructed airway, if core temperature cannot be measured, rescuers can presume asphyxia-induced CA, and should not initiate CPR. If core temperature can be measured, for a victim without signs of life, with a patent airway, and with a core temperature < 30 °C attempt resuscitation, regardless of burial duration.

Oxygenation laryngoscope vs. nasal standard and nasal high flow oxygenation in a technical simulation of apnoeic oxygenation

Background

Failed airway management is the major contributor for anaesthesia-related morbidity and mortality. Cannot-intubate-cannot-ventilate scenarios are the most critical emergency in airway management, and belong to the worst imaginable scenarios in an anaesthetist’s life. In such situations, apnoeic oxygenation might be useful to avoid hypoxaemia. Anaesthesia guidelines recommend careful preoxygenation and application of high flow oxygen in difficult intubation scenarios to prevent episodes of deoxygenation. In this study, we evaluated the decrease in oxygen concentration in a model when using different strategies of oxygenation: using a special oxygenation laryngoscope, nasal oxygen, nasal high flow oxygen, and control.

Methods

In this experimental study we compared no oxygen application as a control, standard pure oxygen application of 10 l·min^− 1 via nasal cannula, high flow 90% oxygen application at 20 l·min^− 1 using a special nasal high flow device, and pure oxygen application via our oxygenation laryngoscope at 10 l·min^− 1. We preoxygenated a simulation lung to 97% oxygen concentration and connected this to the trachea of a manikin model simulating apnoeic oxygenation. Decrease in oxygen concentration in the simulation lung was measured continuously for 20 min.

Results

Oxygen concentration in the simulation lung dropped from 97 ± 1% at baseline to 40 ± 1% in the no oxygen group, to 80 ± 1% in the standard nasal oxygen group, and to 73 ± 2% in the high flow nasal oxygenation group. However, it remained at 96 ± 0% in the oxygenation laryngoscope group (p < 0.001 between all groups).

Conclusions

In this technical simulation, oxygenation via oxygenation laryngoscope was more effective than standard oxygen insufflation via nasal cannula, which was more effective than nasal high flow insufflation of 90% oxygen.

Multiple trauma management in mountain environments - a scoping review : Evidence based guidelines of the International Commission for Mountain Emergency Medicine (ICAR MedCom). Intended for physicians and other advanced life support personnel

Background

Multiple trauma in mountain environments may be associated with increased morbidity and mortality compared to urban environments.

Objective

To provide evidence based guidance to assist rescuers in multiple trauma management in mountain environments.

Eligibility criteria

All articles published on or before September 30th 2019, in all languages, were included. Articles were searched with predefined search terms.

Sources of evidence

PubMed, Cochrane Database of Systematic Reviews and hand searching of relevant studies from the reference list of included articles.

Charting methods

Evidence was searched according to clinically relevant topics and PICO questions.

Results

Two-hundred forty-seven articles met the inclusion criteria. Recommendations were developed and graded according to the evidence-grading system of the American College of Chest Physicians. The manuscript was initially written and discussed by the coauthors. Then it was presented to ICAR MedCom in draft and again in final form for discussion and internal peer review. Finally, in a face-to-face discussion within ICAR MedCom consensus was reached on October 11th 2019, at the ICAR fall meeting in Zakopane, Poland.

Conclusions

Multiple trauma management in mountain environments can be demanding. Safety of the rescuers and the victim has priority. A crABCDE approach, with haemorrhage control first, is central, followed by basic first aid, splinting, immobilisation, analgesia, and insulation. Time for on-site medical treatment must be balanced against the need for rapid transfer to a trauma centre and should be as short as possible. Reduced on-scene times may be achieved with helicopter rescue. Advanced diagnostics (e.g. ultrasound) may be used and treatment continued during transport.

[Statement of the Austrian Society for Anesthesiology, Resuscitation and Intensive Care Medicine (ÖGARI) on the use of laryngeal tubes by ambulancemen and paramedics]

Due to an increasing number of severe complications reported during the prehospital application of laryngeal tubes, the Austrian Society for Anesthesiology, Resuscitation and Intensive Care Medicine (ÖGARI) is prompted to formulate a respective statement. With regard to the current training situation and the applicable laws, ÖGARI recommends to convert the "Emergency Competence for Endotracheal Intubation (NKI)" for emergency paramedics into an "Emergency Competence for Extraglottic Airway Management, (NK-EGA)". Training should include at least 40 h of theoretical instruction, hands-on training on the manikin to secure mastery of the methodology and at least 20 successful applications under clinically elective conditions in adult patients under direct medical supervision. Here, depending on local conditions, both laryngeal mask and laryngeal tube can be used. In the prehospital environment, the device must be used which has been trained as mentioned above. Only 2nd generation EGA should be used. After successful EGA placement timely cuff pressure monitoring and gastric suction should be performed. The use of an EGA by ambulance-men cannot be recommended; these have to be limited to bag-mask ventilation.

[Publications by university Departments of Anaesthesiology from Germany, Austria and Switzerland in 2011-2015 : Scientific publications by university hospitals in D‑A-CH]

BACKGROUND

This study presents a count of publications and citations for all articles published by university Departments of Anaesthesiology in Germany, Austria and Switzerland between 2011 and 2015. The results were compared with former analyses of these countries from 2001-2010 as well as similar international studies.

METHODS

We performed a PubMed search based on PERL-scripts for all publications originating from university Departments of Anaesthesiology in Germany, Austria and Switzerland between 2011 and 2015. According to their author's affiliation, articles were assigned to their affiliated university department. Publications were considered an original article if the category of publication was classified as original research in PubMed. Predatory journals were omitted by using PubMed-listed journals only. Data of citations was retrieved from Thomson Reuter's ISI Web of Knowledge. The following indicators were reported: the number of publications and original articles (counting each author and first authors only) and the share of original articles out of all publications. With regard to citations, we reported the overall number, the percentage of publications, which were cited at least once and the median of citations per publication and per original article as well as the calculated h-index.

RESULTS

The 47 university Departments of Anaesthesiology published 4.697 articles between 2011 and 2015, which make up 89% of all anaesthesiology research originating from Germany, Austria and Switzerland (overall 5.284 publications). Of these, 1.037 (22%) were classified as original articles. Considering only articles with first authors, equalizing a change of PubMed's affiliation field policy in 2012 to compare the numbers with previous periods, 3.709 publications and 821 original articles were published. 90% of all publications and 96% of original articles, respectively, were cited at least once. Publications were cited six times, while original articles were cited nine times. The university department of Anaesthesiology in Zurich published most (n = 245), while most original articles were published in Vienna (n = 77). The highest share of original articles was achieved by Vienna (37%). Publications from Berlin - Benjamin Franklin and Jena (11 citations per publication) and original articles from Essen (23,5 citations per original article) achieved the highest citation rates.

DISCUSSION

In contrast to the worldwide increasing trend, the number of publications of the university Departments of Anaesthesiology in Germany, Austria and Switzerland stagnated. The share of original articles out of all publications continues to decline in comparison to 2001-2010 (-6%). Despite this, original articles were cited more frequently and thus had a higher value for the scientific community. The reasons of the decrease in the number of original articles remain unclear and require further investigation to reverse this negative trend.

CONCLUSION

Strategies to foster academic work in anaesthesiology in Germany, Austria and Switzerland are required.

Publications by Scandinavian university Departments of Anaesthesiology from 2001 to 2015

BACKGROUND

This study assessed the contribution made to research by Scandinavian university Departments of Anaesthesiology and their distribution among those departments.

METHODS

We committed a PubMed search for all publications originating from Scandinavian university Departments of Anaesthesiology between 2001 and 2015. Articles were assigned to their author's affiliated university department and to 3 time periods 2001-2005, 2006-2010 and 2011-2015. The number of publications, original articles and citations were analysed.

RESULTS

The 23 Scandinavian university Departments of Anaesthesiology published 5190 articles between 2001 and 2015, which make up 91.5% from all anaesthesiology research originating from Scandinavia. Of these 1760 (33.9%) were classified as original articles. The number of publications increased in the observed periods (from 1305 in 2001-2005 to 2452 in 2010-2015), but the share of original articles decreased (from 40% to 31%). Finnish university Departments of Anaesthesiology had the largest share of original articles. The university department of Copenhagen was the most productive Department of Anaesthesiology in terms of number of publications (n = 1187) and citation rate of original articles (median 24 citations per original article). Publications from Bergen scored the highest impact (median 19 citations per publication).

CONCLUSIONS

The number of publications from Scandinavian university Departments of Anaesthesiology increased between 2001 and 2015, but the share of original articles decreased. Copenhagen was the most productive university Department of Anaesthesiology based on the number of publications and citations of original articles. Finnish university Departments of Anaesthesiology led in the share of original articles out of all publications.

Cost-utility of extracorporeal membrane oxygenation rewarming in accidentally hypothermic patients-A single-centre retrospective study

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) has become the treatment of choice for severely hypothermic patients in cardiac arrest or acute cardiac failure. Highly specialized ECMO centres have been established, however, no centre has ever reported the costs of extracorporeal rewarming. The aim of this study was to assess the costs of the treatment of patients in Swiss Stage III and IV rewarmed with veno-arterial ECMO.

METHODS

A retrospective exploratory cohort study analysed twenty-nine consecutive patients treated for hypothermia in the Severe Accidental Hypothermia Centre in Cracow, Poland. The main outcome parameters were the overall and specific costs of the ICU treatment of patients rewarmed with veno-arterial ECMO. The secondary outcome parameter was cost utility, determined by the costs involved for every year of life gained. Costs were processed using the bottom-up method and classified into six categories. Survivors were followed up after 1 year.

RESULTS

The mean cost of VA-ECMO was $5133 USD, which equalled 35% of all ICU expenditures ($14 668 USD). One year after discharge, 13 of 29 patients were still alive (45%). The overall gain of life of the thirteen 1-year survivors was 28 years, while the mean cost related to treatment with VA-ECMO for each year of life gained was 1138 USD.

CONCLUSIONS

In this study, the costs of VA-ECMO rewarming and intensive care treatment per patient were substantially lower than in other studies reporting ECMO and intensive care treatment of other causes.

Anesthesia in swine : optimizing a laboratory model to optimize translational research

In order to extrapolate novel therapies from the bench to the bedside (translational research), animal experiments are scientifically necessary. Swine are popular laboratory animals as their cardiorespiratory physiology is very similar to humans. Every study has to be approved by the local and/or national animal ethical committees. As swine are extremely sensitive to stress the primary goal is therefore to provide a calm, stress-free environment in both housing and experimental facilities. Swine should be properly sedated for transport and normothermia needs to be ensured. It is recommended to commence anesthesia by injecting ketamine and propofol followed by endotracheal intubation during spontaneous breathing. After intubation, anesthesia maintenance is performed with morphine or piritramide, propofol and rocuronium and routine monitoring is applied analogue to a clinical operating theater for humans. Normothermia (38.5 °C) needs to be ensured. While surgical procedures can be readily extrapolated from a human operating theater to swine, non-anesthesiologist scientists may lose the animal rapidly due to airway management problems. Vascular access can be secured by cut-downs or ultrasound-guided techniques in the inguinal and the neck region. For humane euthanasia of pigs, morphine, followed by propofol, rocuronium and potassium chloride are recommended. As radical animal right groups may threaten scientists, it is prudent that animal laboratories have unmarked entrance doors, are located in buildings that are not accessible to the public and strictly controlled access of laboratory staff is enforced. In conclusion, swine are an excellent laboratory animal for bench to bedside research and can be managed properly when basic knowledge and adequate skills on careful handling, anesthesia and surgical considerations are present.

[Publication performances of university clinics for anesthesiology: Germany, Austria and Switzerland from 2001 to 2010]

AIM

This study assessed the publication performance of university departments of anesthesiology in Austria, Germany and Switzerland. The number of publications, original articles, impact factors and citations were evaluated.

MATERIAL AND METHODS

A search was performed in PubMed to identify publications related to anesthesiology from 2001 to 2010. All articles from anesthesiology journals listed in the fields of anesthesia/pain therapy, critical care and emergency medicine by the "journal citation report 2013" in Thomson Reuters ISI web of knowledge were included. Articles from non-anaesthesiology journals, where the stem of the word anesthesia (anes*, anaes*, anäst*, anast*) appears in the affiliation field of PubMed, were included as well. The time periods 2001-2005 and 2006-2010 were compared. Articles were allocated to university departments in Austria, Germany and Switzerland via the affiliation field.

RESULTS

A total of 45 university departments in Austria, Germany and Switzerland and 125,979 publications from 2,863 journals (65 anesthesiology journals, 2,798 non-anesthesiology journals) were analyzed. Of the publications 23 % could not be allocated to a given university department of anesthesiology. In the observation period the university department of anesthesiology in Berlin achieved most publications (n = 479) and impact points (1,384), whereas Vienna accumulated most original articles (n = 156). Austria had the most publications per million inhabitants in 2006-2010 (n=50) followed by Switzerland (n=49) and Germany (n=35). The number of publications during the observation period decreased in Germany (0.5 %), Austria (7 %) and Switzerland (8 %). Tables 2 and 4-8 of this article are available at Springer Link under Supplemental.

CONCLUSIONS

The research performance varied among the university departments of anesthesiology in Germany, Austria and Switzerland whereby larger university departments, such as Berlin or Vienna published most. Publication output in Germany, Austria and Switzerland has decreased. Data processing in PubMed should be improved.

[False positive death certification. Does the Lazarus phenomenon partly explain false positive death certification by rescue services in Germany, Austria and Switzerland?]

Apart from misdiagnosis, the Lazarus phenomenon, a spontaneous return of circulation after cardiac arrest, is a potential cause for false positive death certification. Because of medicolegal consequences and thus a negative publication bias, the incidence of false positive death certification is unknown. As a false positive death certification results in criminal prosecution and thus media interest, numerous media archives in Germany, Austria and Switzerland were searched for such reports. A total of nine cases of false positive death certification in these three countries were identified since the early 1990s of which eight occurred in an emergency medical service system setting. Apart from a lack of diligence of emergency physicians, a Lazarus phenomenon could be the reason for such incidents. As definite signs of death will not have developed only a few minutes after stopping CPR it might be difficult for an emergency physician to definitely certify a patient's death in an out-of-hospital setting with 100% safety. Thus, prehospital death certification poses a risk of error and subsequent legal prosecution of the emergency physician, as a Lazarus phenomenon may still occur in this phase. Delegation of death certification from emergency physicians to qualified physicians in a follow-up examination might increase both legal safety for emergency physicians in the field and patient safety.

Optimising the unprotected airway with a prototype Jaw-Thrust-Device--a prospective randomised cross-over study

Despite being a standard procedure during induction of anaesthesia, facemask ventilation can be a major challenge especially for inexperienced anaesthetists. We manufactured a Jaw-Thrust-Device designed to keep the patient's jaws in an optimised position, and thus to maintain the airway in a permanently patent state. Using a cross over design, we compared the influence of using the Esmarch manoeuvre (bimanual jaw-thrust), a nasopharyngeal airway, an oropharyngeal airway, or the Jaw-Thrust-Device on airway physiology in 50 healthy adults with body mass index < 35 kg.m(-2), undergoing standard facemask ventilation for routine induction of anaesthesia. The main study endpoints were expiratory tidal volumes, airway resistances, and gas flow rates. The Jaw-Thrust-Device was more effective in increasing expiratory tidal volumes and peak inspiratory flow than a standard Esmarch manoeuvre, and was more effective than both nasopharyngeal and oropharyngeal airways in decreasing airway resistance.

Retention of mouth-to-mouth, mouth-to-mask and mouth-to-face shield ventilation

BACKGROUND

Retention of mouth-to-mouth, mouth-to-mask and mouth-to-face shield ventilation techniques is poorly understood.

METHODS

A prospective randomised clinical trial was undertaken in January 2004 in 70 candidates randomly assigned to training in mouth-to-mouth, mouth-to-mask or mouth-to-face shield ventilation. Each candidate was trained for 10 min, after which tidal volume, respiratory rate, minute volume, peak airway pressure and the presence or absence of stomach inflation were measured. 58 subjects were reassessed 1 year later and study parameters were recorded again. Data were analysed with ANOVA, chi(2) and McNemar tests.

RESULTS

Tidal volume, minute volume, peak airway pressure, ventilation rate and stomach inflation rate increased significantly at reassessment with all ventilation techniques compared with the initial assessment. However, at reassessment, mean (SD) tidal volume (960 (446) vs 1008 (366) vs 1402 (302) ml; p<0.05), minute volume (12 (5) vs 13 (7) vs 18 (3) l/min; p<0.05), peak airway pressure (14 (8) vs 17 (13) vs 25 (8) cm H(2)O; p<0.05) and stomach inflation rate (63% vs 58% vs 100%; p<0.05) were significantly lower with mouth-to-mask and mouth-to-face shield ventilation than with mouth-to-mouth ventilation. The ventilation rate at reassessment did not differ significantly between the ventilation techniques.

CONCLUSIONS

One year after a single episode of ventilation training, lay persons tended to hyperventilate; however, the degree of hyperventilation and resulting stomach inflation were lower when a mouth-to-mask or a face shield device was employed. Regular training is therefore required to retain ventilation skills; retention of skills may be better with ventilation devices.

Fatal errors in nitrous oxide delivery

Nitrous oxide continues to be used frequently and the possibility of inadvertent fatal hypoxaemia resulting from technical errors with its administration still exists. A Medline analysis revealed only a few case reports over the last 30 years, and a closed claim analysis only reported 'claims involving oxygen supply lines' predating 1990. The aim of this study was to assess the frequency of nitrous oxide-related catastrophes during general anaesthesia in Germany, Austria, and Switzerland. As nitrous oxide-related anaesthesia casualties are rare but generally prosecuted, they almost invariably attract significant media attention. We scanned mass media archives from April 2004 until October 2006 for nitrous oxide-related disasters during general anaesthesia. This approach detected six incidents which were almost certainly nitrous oxide ventilation-related deaths. Searching non-scientific data bases demonstrates that severe incidents involving oxygen supply lines occurred after 1990, and may be much more frequent than previously thought.

Head position for opening the upper airway

Inexperienced rescuers may encounter severe problems in an unconscious patient with opening and maintaining a patent upper airway. Designing a ventilating device that could indicate how to open an upper airway correctly may be beneficial. The heads of 102 volunteers were randomly placed in different head positions by one investigator. A pocket mask was then pressed gently on the volunteer's face followed by measurement of the head position angles. Mean (SD) flexion was - 4 degrees (8 degrees) (95% CI - 5.9 to - 2.9); the mean neutral position was 21 degrees (6 degrees) (95% CI, 19.9 to 22.3); extension was 42 degrees (6 degrees) (95% CI 40.8 to 43.0 degrees) and differed significantly between each position (p < 0.001). The flexion and neutral position angles were significantly greater in men than in women: - 2 (7 degrees) vs. -8 (7 degrees) and 22 (7 degrees) vs 20 (5 degrees); p < 0.001 and p = 0.03, respectively. Maximum extension of the head in both supine men and women was 42 degrees, which could be utilised to optimise assisted ventilation of an unprotected upper airway.

Beatmung eines ungeschützten Atemwegs

BACKGROUND

Currently 30 chest compressions and 2 ventilations with an inspiratory time of 1 s are recommended during cardiopulmonary resuscitation with an unprotected airway, thus spending about 15% instead of 40% of resuscitation time on ventilation. Time could be gained for chest compressions when reducing inspiratory time from 2 s to 1 s, however, stomach inflation may increase as well.

METHODS

In an established bench model we evaluated the effect of reducing inspiratory time from 2 s to 1 s at different lower oesophageal sphincter pressure (LOSP) levels using a novel peak inspiratory-flow and peak airway-pressure-limiting bag-valve-mask device (Smart-Bag).

RESULTS

A reduction of inspiratory time from 2 s to 1 s resulted in significantly lower peak airway pressure with LOSP of 0.49 kPa (5 cm H2O), 0.98 kPa (10 cm H2O) and 1.47 kPa (15 cm H2O) and an increase with 1.96 kPa (20 cm H2O). Lung tidal volume was reduced with 1 s compared to 2 s. When reducing inspiratory time from 2 s to 1 s, stomach inflation occurred only at a LOSP of 0.49 kPa (5 cm H2O).

CONCLUSIONS

In this model of a simulated unprotected airway, a reduction of inspiratory time from 2 s to 1 s using the Smart-Bag resulted in comparable inspiratory peak airway pressure and lower, but clinically comparable, lung tidal volume. Stomach inflation occurred only at a LOSP of 0.49 kPa (5 cm H2O), and was higher with an inspiratory time of 2 s vs 1 s.

Der Lawinennotfall

In North America and Europe around 140 persons die every year due to avalanches, approximately 35 in North America, 100 in the European Alps, and 5 in other parts of Europe. Most of the victims are skiers and snowboarders. This article outlines the specific pathophysiology of avalanche burials, such as hypoxia, hypercapnia, and hypothermia and also other factors which influence survival. Strategies to minimize the mortality due to avalanches and the on-site treatment of buried persons are discussed. Finally, possibilities to reduce the number of avalanche deaths are pointed out.

Maskenbeatmung als Rückzugsstrategie zur endotrachealen Intubation

The goal of ventilation in an unprotected airway is to optimize oxygenation and carbon dioxide elimination of the patient. This can be achieved with techniques such as mouth-to-mouth ventilation, but preferably with bag-valve-mask ventilation. Securing the airway with an endotracheal tube is the gold standard, but excellent success in emergency airway management depends on initial training, retraining, and actual frequency of a given procedure in the routine. "Patients do not die from failure to intubate; they die from failure to stop trying to intubate or from undiagnosed oesophageal intubation" (Scott 1986). Therefore, adequate face mask ventilation has absolute priority in airway management by an unexperienced rescuer. During ventilation of an unprotected airway, stomach inflation and subsequent severe complications may result. Careful ventilation can be performed with low inspiratory pressure and flow, and subsequently with a low tidal volume at a high inspiratory fraction of oxygen. This could be a strategy to achieve more patient safety.